I. Field of the Invention
The present invention relates to a freeze proof faucet adapted to be mounted to an exterior wall.
II. Description of the Prior Art
There are a number of previously known faucets which are mounted to an exterior wall so that the outlet from the faucet is positioned outside the wall and thus exposed to the elements. In many of these previously known faucets, the valve assembly which opens and closes the faucet is positioned on the exterior side of the wall. Consequently, in cold climates the water contained within the faucet upstream from the valve assembly can freeze and result in damage or even destruction of the faucet.
There have, however, been a number of previously known faucets which are designed specifically to prevent freezing of water within the faucet in cold climates. Such faucets typically comprise an elongated housing which extends inwardly from the exterior surface of the wall so that the inner end of the housing is positioned within a relatively warm zone of the building structure despite cold weather outside. Furthermore, these previously known freeze proof faucets include a valve seat and a valve member positioned closely adjacent the innermost end of the housing. Since the innermost end of the housing is positioned within a relatively warm zone of the building structure, freezing of the water upstream from the valve and valve seat is prevented.
The other or outer end of the valve member for these previously known freeze proof faucets are typically externally threaded and threadably cooperated with internal threads formed in the valve housing adjacent its outermost end. A handle is secured to the outer end so that rotation of the handle simultaneously rotates and axially displaces the valve member between an open and closed position.
The housing as well as the valve member for these previously known freeze proof faucets have typically been constructed of metal, such as brass, and, therefore, are relatively expensive in construction. The construction of the major components of the faucet, and particularly the valve member, from plastic advantageously reduces the overall cost of the valve assembly. It has not been previously possible, however, to construct the valve member from plastic since, due to the elongated length of the valve member in a freeze proof faucet, a plastic valve member tends to bind within the housing after extended use and is unable to withstand the necessary twisting or torsional forces imposed on the valve member.
A still further disadvantage of these previously known metal freeze proof faucets is that metal has a high thermal conductivity. As such, under extremely cold conditions the water can still freeze at the innermost end of the faucet, particularly if there is little or no warm air circulation around the faucet.